The following figure shows the Single Channel Emulator within the system overview:

Challenges

The objective is to develop Space Single Channel Simulator usable by all telecommunication satellite operators.

The key drivers are the ability to process a large bandwidth (600MHz), to implement specific link conditions foot pools of terminals and also to be operator friendly.

Benefits

The demand of a new class of Satellite Payload channel emulators appears with the emergence of complex Multi-spot payloads which require extra care for system configuration and validation, including :

- A very wide instantaneous bandwidth (over 500 MHz)

- The emulation of the end to end satellite channel (uplink, downlink and payload impairments), taking into account all the preponderant effects in the link budget.

- The simultaneous emulation of different propagation conditions (up to 4 in Space SCE, with possibilities of further evolution), that allows the simulation of system capabilities such as Fade Mitigation Techniques.

- A very important quantity of connected terminals (up to 300).

Most of the demand for this kind of new product “Space-SCE” comes from satellite operators. However, it is considered broadening the potential customers by proposing a product that would also suit needs of the industrials (satellite manufacturers, terminal/VSAT modem suppliers...), in terms of system integration and validation.

The key factors identified, that make a product attractive:

- the performances to be reached in terms of bandwidth and emulated impairments.

- the level of abstraction of human-machine interface, usable by operators not necessarily aware of the full system definition or behavior.

Features

In order to configure the Single Channel Emulator, a dedicated graphic user interface is developed, to enable the user to configure all the required parameters of the Space-SCE, to run a pre-programmed scenario and to collect emulation results.

Main drivers for Space-SCE development are :

- The ability to process a large bandwidth (600MHz) is clearly the key driver of the Space-SCE design. In particular, the nonlinear effects of the channel that are created by the amplifier function do require to work on the whole channel bandwidth to be realistic.

- The Space-SCE is able to further evolve and adapt to various broadband payloads and systems. All the effects that are emulated by the Single Channel Emulator are digitally processed.

- The Space-SCE is able to implement specific link conditions foot pools of terminals. On a given user RF link, some impairments are not the same, depending on the location of each terminal under the spot beam.

- The Space-SCE is operator friendly

System Architecture

The Space-SCE is designed to connect to real gateways and terminals, replacing completely the real satellite payload. On the Forward link, it processes a signal spanning up to 600 MHz bandwidth delivered by the Gateway, and delivers the aggregated spectrum to terminals where each band has a programmable central frequency.
The Space-SCE is designed to be representative of all transmission conditions.
The main sub-function blocks are :
- Payload Channel Emulator (PCE)
The PCE emulates all the effects of propagation and payload impairments on a very large bandwidth.
- Scenario configuration and scheduling tool (SCS)
The scenario configuration and scheduling tool handles :
- the configuration of an emulation scenario
- the scheduling of these emulation scenarii
- Payload Traffic Manager (PTM)
The PTM adds a high level of operability, in order to create an operational deployment of the terminals, and to create / evaluate the RF parameters that are associated to this deployment.
- Communication System Monitoring (CSM)
The CSM tool allows to monitor the signal at PCE output in L Band. A specific interface is designed to embed this already developed product in the Space-SCE.
- Satellite Data Base
The Satellite Data Base hosts the RF characteristics of the equipment embedded in the payload.

Plan

Design Phase:

This phase aims at defining a complete Design of the targeted solution for a Space-SCE.

Development and validation phase:

When the Space-SCE design is considered as mature, an industrial prototype version is developed and tested.

Current status

The project has been completed from design phase to operational hardware and software testing. A model is to be delivered soon for a commercial service.